The AMD case with 10/200 acuity includes a JND value of 2.00. This value represents the smallest change in diopters that the patient can detect.

• A. True
• B. False
• C. Cannot be determined
• D. It refers to axis change

Answer: (A)

The key idea is that JND here refers to the perceptual threshold for changes in lens power, measured in diopters. A JND of 2.00 means the patient can detect a difference when the refractive power changes by about 2 diopters. This is about sensitivity to changes in focus, not about how large or small the acuity is, and not about the orientation of astigmatism.

So in this AMD case, the value 2.00 D represents the smallest change in lens power that the patient can notice, which makes the statement true. It’s not about axis, which would relate to astigmatic orientation, not the magnitude of refractive change. Therefore, the other interpretations don’t fit.